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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Functions to access SY3686A power management chip temperature4 *5 * Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/6 *7 * Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>8 * Alistair Francis <alistair@alistair23.me>9 */10 11#include <linux/err.h>12#include <linux/hwmon.h>13#include <linux/init.h>14#include <linux/module.h>15#include <linux/platform_device.h>16#include <linux/regmap.h>17#include <linux/regulator/machine.h>18 19#include <linux/mfd/sy7636a.h>20 21static int sy7636a_read(struct device *dev, enum hwmon_sensor_types type,22 u32 attr, int channel, long *temp)23{24 struct regmap *regmap = dev_get_drvdata(dev);25 int ret, reg_val;26 27 ret = regmap_read(regmap,28 SY7636A_REG_TERMISTOR_READOUT, ®_val);29 if (ret)30 return ret;31 32 *temp = reg_val * 1000;33 34 return 0;35}36 37static umode_t sy7636a_is_visible(const void *data,38 enum hwmon_sensor_types type,39 u32 attr, int channel)40{41 if (type != hwmon_temp)42 return 0;43 44 if (attr != hwmon_temp_input)45 return 0;46 47 return 0444;48}49 50static const struct hwmon_ops sy7636a_hwmon_ops = {51 .is_visible = sy7636a_is_visible,52 .read = sy7636a_read,53};54 55static const struct hwmon_channel_info * const sy7636a_info[] = {56 HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),57 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),58 NULL59};60 61static const struct hwmon_chip_info sy7636a_chip_info = {62 .ops = &sy7636a_hwmon_ops,63 .info = sy7636a_info,64};65 66static int sy7636a_sensor_probe(struct platform_device *pdev)67{68 struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);69 struct regulator *regulator;70 struct device *hwmon_dev;71 int err;72 73 if (!regmap)74 return -EPROBE_DEFER;75 76 regulator = devm_regulator_get(&pdev->dev, "vcom");77 if (IS_ERR(regulator))78 return PTR_ERR(regulator);79 80 err = regulator_enable(regulator);81 if (err)82 return err;83 84 hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,85 "sy7636a_temperature", regmap,86 &sy7636a_chip_info, NULL);87 88 if (IS_ERR(hwmon_dev)) {89 err = PTR_ERR(hwmon_dev);90 dev_err(&pdev->dev, "Unable to register hwmon device, returned %d\n", err);91 return err;92 }93 94 return 0;95}96 97static struct platform_driver sy7636a_sensor_driver = {98 .probe = sy7636a_sensor_probe,99 .driver = {100 .name = "sy7636a-temperature",101 },102};103module_platform_driver(sy7636a_sensor_driver);104 105MODULE_DESCRIPTION("SY7636A sensor driver");106MODULE_LICENSE("GPL");107